A lighting device, such as a lamp, is installed in a vehicle so as to assist a driver to secure a field of vision by increasing surrounding illumination intensity or notify a current driving state of the vehicle to the outside.
The lighting device installed in the vehicle (hereinafter, referred to as a lighting device for a vehicle) may include a head lamp which emits light toward the front of the vehicle, and a rear lamp which indicates the direction of travel of the vehicle or notifies the operation or non-operation of a brake.
The lighting device for a vehicle may form a low beam or a high beam to ensure a driver's field of vision during night driving. Recently, the use of light-emitting diodes (LEDs) having high power efficiency and a long lifespan tends to increase.
Meanwhile, a laser diode with an irradiation distance longer than that of an LED can be used as a light source of the lighting device for a vehicle.